Peripheral sterile corneal infiltrates after refractive surgery

Wessely corneal ring phenomenon: An unsolved pathophysiological dilemma

The cornea is a densely innervated, avascular tissue showing exceptional inflammatory and immune responses. The cornea is a site of lymphangiogenic and angiogenic privilege devoid of blood and lymphatic vessels that limits the entry of inflammatory cells from the adjacent and highly immunoreactive conjunctiva. Immunological and anatomical differences between the central and peripheral cornea are also necessary to sustain passive immune privilege. The lower density of antigen-presenting cells in the central cornea and the 5:1 peripheral-to-central corneal ratio of C1 are 2 main features conferring passive immune privilege. C1 activates the complement system by antigen-antibody complexes more effectively in the peripheral cornea and, thus, protects the central corneas' transparency from immune-driven and inflammatory reactions. Wessely rings, also known as corneal immune rings, are non-infectious ring-shaped stromal infiltrates usually formed in the peripheral cornea. They result from a hypersensitivity reaction to foreign antigens, including those of microorganism origin. Thus, they are thought to be composed of inflammatory cells and antigen-antibody complexes. Corneal immune rings have been associated with various infectious and non-infectious causes, including foreign bodies, contact lens wear, refractive procedures, and drugs. We describe the anatomical and immunologic basis underlying Wessely ring formation, its causes, clinical presentation, and management.

Keratitis following laser refractive surgery: Clinical spectrum, prevention and management

Laser refractive surgery (LRS) is one of the most demanding areas of ophthalmic surgery and high level of precision is required to meet outcome expectations of patients. Post-operative recovery is of vital importance. Keratitis occurring after LRS can delay visual recovery. Both surface ablations [Photorefractive keratectomy (PRK)] as well as flap procedures [Laser in-situ keratomileusis (LASIK)/Small incision lenticule extraction] are prone to this complication. Reported incidence of post-LRS infectious keratitis is between 0% and 1.5%. The rate of infections after PRK seems to be higher than that after LASIK. Staphylococci, streptococci, and mycobacteria are the common etiological organisms. About 50–60% of patients present within the first week of surgery. Of the non-infectious keratitis, diffuse lamellar keratitis (DLK) is the most common with reported rates between 0.4% and 4.38%. The incidence of DLK seems to be higher with femtosecond LASIK than with microkeratome LASIK. A lot of stress is laid on prevention of this complication through proper case selection, asepsis, and use of improved protocols. Once keratitis develops, the right approach can help resolve this condition quickly. In cases of suspected microbial keratitis, laboratory identification of the organism is important. Most lesions resolve with medical management alone. Interface irrigation, flap amputation, collagen cross-linking and therapeutic penetrating keratoplasty (TPK) are reserved for severe/non-resolving cases. About 50–75% of all infectious keratitis cases post LRS resolve with a final vision of 20/40 or greater. Improved awareness, early diagnosis, and appropriate intervention can help limit the damage to cornea and preserve vision.

Marginal Keratitis with Secondary Diffuse Lamellar Keratitis After Small Incision Lenticule Extraction (SMILE) After Initiation of Continuous Positive Airway Pressure (CPAP) Therapy

Marginal keratitis, also known as catarrhal infiltrates, is a common, self-limiting condition characterized by inflammation at the peripheral aspect of the cornea. This non-infectious process is most typically a reaction to bacteria such as Staphylococcus, and results from a cell-mediated immune response to the bacterial antigens. This hypersensitivity reaction leads to the formation of stromal infiltrates that run parallel to the limbus. These infiltrates may extend around the limbal edge and can lead to the formation of marginal ulcers. Often the patient will have associated blepharoconjunctivitis. Both marginal keratitis and blepharoconjunctivitis are treated with topical steroids, with or without antibiotics, and good lid hygiene. We report a case of a patient who previously underwent small incision lenticule extraction (SMILE) who presented with marginal keratitis and secondary diffuse lamellar keratitis (DLK) in the right eye following recent initiation of continuous positive airway pressure (CPAP) therapy. There was no antecedent ocular trauma. With the initiation of steroid therapy, the patient returned to baseline visual acuity within one week. Though recurrence may be common in cases of marginal keratitis, our patient has not had any recurrence of symptoms or disease. DLK has previously been reported in the literature; however, there has been no reported case of marginal keratitis with secondary DLK after initiation of CPAP therapy to date.

Visual outcomes of sterile corneal infiltrates after photorefractive keratectomy

Purpose:

Sterile infiltrates following laser refractive surgery is an uncommon complication. This study was undertaken to analyze the visual outcomes of sterile infiltrates following photorefractive keratectomy (PRK).

Methods:

This retrospective study included 14 eyes that developed sterile infiltrates following PRK out of a total of 6280 eyes that underwent PRK between 2014 and 2017. Medical records of these patients, including patient demographics, characteristics of the infiltrate, presenting visual acuity, and treatment outcomes were recorded and analyzed.

Results:

The incidence of sterile corneal infiltrates post-PRK in our study was 0.22% (14/6280). The mean age of the patients was 27.42 ± 4.87 years. The uncorrected visual acuity (UCVA) at presentation was 0.49 ± 0.13 log MAR units. The mean size of the infiltrate was 3.22 ± 2.85 mm². All cases were successfully managed medically with topical steroids. The mean UCVA and best-corrected visual acuity (BCVA) at the last follow-up visit were 0.08 ± 0.08 and 0.05 ± 0.07 log MAR units, respectively. The mean time taken for resolution of the infiltrate was 8.91 ± 4.57 days.

Conclusion:

Sterile infiltrates following PRK can be effectively treated with aggressive topical steroids. The outcome is generally favorable and does not require surgical intervention if treatment is instituted early.

Hypersensitivity reactions after femtosecond laser small incision lenticule extraction: a case report of corneal infiltrates

BACKGROUND

Femtosecond laser corneal refractive surgery is generally considered safe and effective; however, this procedure is rarely associated with severe allergic reactions. We reported a rare case of hypersensitivity reactions which caused bilateral peripheral corneal infiltrates after femtosecond laser small incision lenticule (SMILE) surgery in a man with a history of fruits allergy.

CASE PRESENTATION

Here we report the case of a young man who developed white, ring-shaped bilateral peripheral infiltrates that appeared 1 day after an uneventful SMILE surgery. The overlying corneal epithelium was intact; the infiltrate was negative for bacterial culture, but high titers of immunoglobulin E was demonstrated in the blood. Symptomatically, a clinical diagnosis of sterile corneal infiltrates was made, and the patient was treated with topical and systemic steroids. The infiltrates were immunogenic in origin, which may be caused by the contact lenses used for suction duration in surgery. It resolved without corneal scarring in the subsequent months following steroid treatment. The patient's visual acuity improved.

CONCLUSIONS

When patients with a history of allergy who aim to perform corneal refractive surgery, surgeons must consider possible hypersensitivity reactions after treatment. More studies are needed to clarify the relationship between contact glass used in femtosecond laser corneal refractive surgery and IgE mediated hypersensitivity reactions.

Sterile corneal infiltrates after corneal collagen cross-linking: evaluation of risk factors

PURPOSE

To evaluate possible risk factors leading to sterile corneal infiltrates following corneal collagen cross-linking (CXL).

METHODS

A total of 588 eyes of 459 patients treated with Epi-off (n = 461) or Epi-on (n = 127) CXL were retrospectively evaluated. Risk factors, including preoperative blepharitis and vernal conjunctivitis, the postoperative use of topical non-steroidal anti-inflammatory drugs (NSAIDs), as well as Kmax and pachymetry measurements, were assessed. In vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) analyses were performed in patients with sterile infiltrates.

RESULTS

Sterile infiltrates developed in 19 cases (3.2%). No patients in the Epi-on group developed sterile infiltrates. The evaluation of acceleration of the CXL procedure as a risk factor revealed no specific difference in the incidence of infiltrates among four different Epi-off groups (3 mW/cm² -30 min, 9 mW/cm² -10 min, 18 mW/cm² -5 min, 30 mW/cm² -4 min procedures; p > 0.05, all). Blepharitis, vernal conjunctivitis, Kmax and pachymetry were not identified as risk factors (p > 0.05). Postoperative use of NSAIDs was a significant contributor (p = 0.007), and it increased the chance of sterile infiltrates 4.09 times (95% CI, 1.463-11.428). In vivo confocal microscopy (IVCM) showed non-specific inflammation with dendritic cells at the epithelium and at Bowman's layer. In AS-OCT, a hyper-reflective band at the level of the anterior stroma to a depth of 100-140 μm was observed.

CONCLUSION

The evaluation of the risk factors such as blepharitis, the use of NSAIDs, vernal conjunctivitis, the duration of CXL procedure and amount of light intensity showed that epithelial damage is possibly the common pathway in the pathogenesis, as no sterile infiltrates in Epi-on CXL occurred, and the postoperative use of NSAIDs increased the risk of developing sterile infiltrates about four times.

Sterile Corneal Infiltrates Secondary to Psoriasis Exacerbations: Topical Tacrolimus as an Alternative Treatment Option

INTRODUCTION

Psoriasis is a common chronic inflammatory skin disease. Ocular manifestations, which occur in 10% to 20% of cases of psoriasis, are usually bilateral and often present during an exacerbation of the psoriasis. Serious corneal involvement is rare but can be devastating.

CASE REPORT

Two cases of sterile corneal infiltrates secondary to an exacerbation of psoriasis are presented. Treatment involved the use of 0.02% topical tacrolimus ointment, which resulted in resolution of the symptoms and infiltrates.

DISCUSSION AND CONCLUSION

Topical tacrolimus may be considered as an alternative treatment option to corticosteroids in sterile corneal infiltrates.

Corneal inlay implantation complicated by infectious keratitis

BACKGROUND/AIMS

To report five cases of infectious keratitis following corneal inlay implantation for the surgical correction of presbyopia.

METHODS

This was a retrospective, observational case series. Five eyes of five patients were identified consecutively in two emergency departments during a 1-year period, from November 2013 to November 2014. Patients' demographics, clinical features, treatment and outcomes are described.

RESULTS

There were four female patients and one male, aged 52-64 years. Three patients had the KAMRA inlay (AcuFocus) and two had the Flexivue Microlens inlay (Presbia Coöperatief U.A.) inserted for the treatment of presbyopia and they presented from 6 days to 4 months postoperatively. Presenting uncorrected vision ranged from 6/38 to counting fingers. One patient's corneal scrapings were positive for a putatively causative organism, Corynebacterium pseudodiphtheriticum, and all patients responded to broad-spectrum fortified topical antibiotics. All patients lost vision with final uncorrected visual acuity ranging from 6/12 to 6/60 and best-corrected vision ranging from 6/7.5 to 6/12. Two patients' corneal inlays were explanted and three remained in situ at last follow-up.

CONCLUSIONS

Infectious keratitis can occur at an early or late stage following corneal inlay implantation. Final visual acuity can be limited by stromal scarring; in the cases where the infiltrate was small and off the visual axis at the time of presentation, the final visual acuity was better than those patients who presented with larger lesions affecting the visual axis. Though infection may necessitate removal of the inlay, early positive response to treatment may enable the inlay to be left in situ.

Complications of femtosecond-assisted laser in-situ keratomileusis flaps

Femtosecond-assisted laser in-situ keratomileusis flaps have revolutionized refractive surgery since their introduction. Although these lasers are exceedingly safe, complications still do occur. This review focuses specifically on examining the literature and evidence for flap complications during femtosecond-assisted laser in-situ keratomileusis as well as their management.

Severe bilateral paralimbal sterile infiltrates after photorefractive keratectomy

This study presents a case report of the clinical presentation and management of a 47-year-old male myope who underwent photorefractive keratectomy (PRK) and developed bilateral sterile corneal infiltrates at 1 day post-operatively. The patient was successfully treated with aggressive topical antibiotic and topical steroid therapy. The final corrected distance visual acuity (CDVA) was 20/25 with faint corneal scarring. Peripheral sterile corneal infiltrate can occur after PRK with excellent prognosis. Infectious causes should be suspected in all cases of corneal infiltrate. The most likely cause of peripheral sterile corneal infiltrate in this case was pooling of the tear film containing antigens under the bandage contact lens.

LASIK interface keratitis: epidemiology, diagnosis and care

PURPOSE OF REVIEW

Diffuse lamellar keratitis (DLK) is one of the more common interface complications occurs after laser in-situ keratomileusis (LASIK). The diagnosis can sometimes be challenging, as the differential diagnosis includes infectious keratitis, which requires a completely different treatment compared to DLK. This review assesses our current knowledge of the epidemiology, diagnosis and treatment of DLK.

RECENT FINDINGS

DLK occurs during the immediate postoperative period, but there are also late-onset cases. Early cases can occur in outbreaks, related to exogenous factors. Late-onset cases are most often related to inciting factors. Over time, case reports and series have reported DLK onset occurring further after surgery. It is probable that additional inciting factors will also be reported over time. Visual outcomes following DLK tend to be good when the condition is diagnosed properly and treated with intensive topical or systemic steroids, possibly combined with interface irrigation.

SUMMARY

DLK is a well recognized and well described complication occurring after LASIK. Associated inciting and risk factors and treatment algorithms have been described, but additional questions remain. Our knowledge and our patients will benefit from further research and development of evidence-based treatments.

Efficacy and tolerability of a fixed-dose moxifloxacin - dexamethasone formulation for topical prophylaxis in LASIK: a comparative, double-masked clinical trial

Purpose

To compare the efficacy and tolerability of a fixed-dose combination of 0.5% moxifloxacin and 0.1% dexamethasone formulation (MFLX/DEX) vs conventional dosing with both agents dosed separately for prophylaxis after laser-assisted in situ keratomileusis (LASIK).

Methods

A prospective, randomized, double-masked, parallel-group study of 64 patients undergoing bilateral LASIK. Patients received either combined MFLX/DEX and placebo or moxifloxacin and dexamethasone dosed separately in both eyes. Baseline and postoperative assessments were made on surgery days –2, 1, 3, 8, and 15 and consisted of uncorrected visual acuity (UCVA), intraocular pressure (IOP), severity of inflammation, endothelial cell loss, ocular pain, burning, and itching sensation. The posterior segment was evaluated at the screening and exit visits.

Results

Of the 64 patients treated, 7 eyes did not meet the inclusion criteria and were excluded from the analysis. No ocular infection or persistent inflammation developed. Postoperatively there were no statistical differences between treatments for most parameters measured. More eyes in the combined MFLX/DEX group reported pruritus and burning post operatively; however, differences were also observed at baseline.

Conclusion

Topical prophylaxis with MFLX/DEX eye drops was well tolerated and is therapeutically equivalent to conventional dosing with moxifloxacin and dexamethasone from individual bottles.

Peripheral sterile corneal infiltrate in two brothers after photorefractive keratectomy

This is a report of two brothers who underwent bilateral photorefractive keratectomy and developed bilateral peripheral corneal infiltrate on the third day following surgery. The patients were treated with antibiotics and low concentration steroid until negative culture was reported 48 h later, when intensive topical steroid was started. The infiltrate resolved by day 10 with residual subepithelial haze that was apparent 8 months after surgery. Sterile infiltrate has been reported as complication of photorefractive keratectomy and can be managed successfully with excellent outcome. The fact that it happened in two brothers may raise the possibility of genetic predisposition.

Bilateral peripheral infiltrative keratitis after LASIK

PURPOSE

To present a case of peripheral infiltrative keratitis mimicking infectious keratitis on the flap margin and limbus, which appeared on the first postoperative day after the laser in situ keratomileusis (LASIK).

METHODS

A 36-year-old woman who underwent uneventful bilateral simultaneous LASIK developed multiple round infiltrate along the flap margin reaching to limbus from the 11 o'clock to 6 o'clock area in both eyes.

RESULTS

The flap was lifted and irrigation was performed with antibiotics. but infiltration seemed to appear again. The infiltrate was more concentrated at the periphery and was extended to the limbus. Direct smear and culture for bacteria and fungus were negative. Topical prednisolone acetate 1% eye drops was added, infiltrative condition was resolved.

CONCLUSIONS

LASIK induced peripheral infiltrative keratitis, in which infectious origin was ruled out, is reported.